In the production and packaging of many goods in containers such as jars and cans, particularly food products that have a limited shelf life, it is necessary to provide label information such as the date at which the goods may be considered as stale or unsaleable. Printing devices for providing such label information must be capable of continuous, rapid operation for long periods of time and with a high degree of reliability. Moreover, such printer devices or coders must provide a clear and highly readable impression on the production article label without smearing even though the production line is moving at a high rate of speed.
A general object of the present invention is to provide an in-line printing device that fulfills the aforesaid desired requirements.
Another object of the present invention is to provide a printing device or coder that is adaptable for either continuous operation on a conveying line of production articles or for intermittent operation on other articles that are temporarily positioned for printing adjacent to the device.
Another object of the present invention is to provide an in-line printing device that is comprised of a unique combination of elements having relatively low inertia characteristics, thereby making them capable of rapid acceleration and deceleration and allowing the device to operate efficiently at high speeds with minimum wear and vibration.
Another object of the present invention is to provide an in-line printing device wherein the printing type contacts an inking wheel between each printing cycle in such a manner that only a minimum amount of ink is used thereon so that smearing is avoided during printing and a clear imprint is provided even for relatively small type.
Yet another object of the present invention is to provide an in-line printing device which may be powered by a motor or some other driving power source that runs at a constant speed and yet wherein the printing is accomplished while the type remains momentarily motionless in a fixed predetermined position.
Another object of the present invention is to provide an in-line printing device which is particularly adapted for use with a roll-on type label application machine for jars or cans.
Still another object of the invention is to provide an in-line printing device which allows the use of a wide range of type forms and sizes, either flexible or rigid, including the use of relatively small type without the usual requirement of high application pressure.